On Sun, 1 Dec 2019 09:49:40 -0800 (PST), in gmane.comp.hardware.beagleboard.user Wojciech B <[email protected]> wrote: >Thank you for the answer. I also found that my LI-Ion have additional >internal protection and they simply do not allow overcharging so I hope I >am on the safe site. >What is the reason for 5 hours limit? Assuming I have 3000mAH battery and >500mA charger it would always take longer to charge battery. >Regards, >W > https://batteryuniversity.com/learn/article/charging_lithium_ion_batteries """ The advised charge rate of an Energy Cell is between 0.5C and 1C; the complete charge time is about 2–3 hours. Manufacturers of these cells recommend charging at 0.8C ... """ """ Li-ion cannot absorb overcharge. When fully charged, the charge current must be cut off. A continuous trickle charge would cause plating of metallic lithium and compromise safety """ https://batteryuniversity.com/learn/article/how_to_prolong_lithium_based_batteries
https://www.powerstream.com/li.htm """ The lithium ion battery is easy to charge. Charging safely is a more difficult. The basic algorithm is to charge at constant current (0.2 C to 0.7 C depending on manufacturer) until the battery reaches 4.2 Vpc (volts per cell), and hold the voltage at 4.2 volts until the charge current has dropped to 10% of the initial charge rate. The termination condition is the drop in charge current to 10%. The top charging voltage and the termination current varies slightly with the manufacturer. However, a charge timer should be included for safety. The charge cannot be terminated on a voltage. The capacity reached at 4.2 Volts per cell is only 40 to 70% of full capacity unless charged very slowly. For this reason you need to continue to charge until the current drops, and to terminate on the low current. """ """ When the charge rate during the constant current phase is low, the charger process will spend less time during the constant voltage tail. If you charge below about 0.18 C, the cell is virtually full when the 4.2 volts is reached. This can be used as an alternative charge algorithm. Just charge below 0.18C constant current and terminate the charge when the voltage reaches 4.2 volts per cell. """ On a 3000mAH battery, 0.18C is 540mA, so a 500mA charger would be following this simplified algorithm -- you just need to monitor voltage and kill the charger as appropriate. -- Dennis L Bieber -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/beagleboard/g7naue9v9idocnnlppvkl1dqiafb92gbnh%404ax.com.
